(a) Field of the Invention
The present invention relates to a USB (Universal Serial Bus) connector and more particularly, to a micro USB socket connector, which comprises a plastic core member having multiple metal terminals embedded therein and a metal casing that houses the plastic cover member, wherein the plastic core member has a constraint device, for example, a raised portion forced into engagement with a matching constraint device, for example, a notch of the metal casing, and the metal casing has two rear extension arms bent inwards or downwards to hold down the plastic cover member.
(b) Description of the Prior Art
A micro USB (Universal Series Bus) connector has a dimension smaller than a mini USB connector. Micro USB is a new generation specification of mini USB, having a dimension reduced by 60% when compared to mini USB. For the advantages of lower profile and high power characteristics, micro USB is practical for use in small electronics (such as cell phone, digital camera, PDA, or mobile music player to provide a high-speed data transmission or battery charging function.
In actual use, a micro USB connector is frequently plugged and unplugged. Therefore, a micro USB connector must be more durable than a mini USB connector to pass the more critical twist test than ever before, which means the capability of being plugged and unplugged of a micro USB must be over 10,000 times.
A regular micro USB socket connector is generally comprised of a metal casing, a plastic core member mounted in the metal casing, and a plurality of metal terminals bonded to the plastic core member. When in use, a micro USB socket connector is bonded to a circuit board. After a certain number of times in plugging and unplugging, both the connection between the metal casing and the circuit board and that between the plastic core member and the metal casing may be loosened, resulting in a connection error.